Jessica Ennis won the 100m hurdles and the high jump at the British Olympic trials. Photograph: Joe Toth/BPI/Corbis

Jessica Ennis's sharp start to the Olympic summer continued here at the Aviva trials on Saturday in Birmingham. She easily won both the events she was competing in, the high jump and the 100m hurdles. She will be back at the track on Sunday, trying to add a third title in the long jump too.

Following on from the new national heptathlon record she set in Götzis a few weeks back, her performances only added to the feeling that, a month out from the start of the Games, she is in the form of her life.

The wins were impressive in their way. The high jump had been the one weak link in the seven events she competed at in Götzis. Then she could only clear 1.85m, 10cm below her personal best. "The high jump needed some sharpening up," Ennis admitted. She and her coach, Toni Minichello, have been tinkering with her runup, and it seems to have helped. That said, Ennis was worried in her warm-up. "I thought it was going to be terrible because I just couldn't get over the bar."

When the competition started though, Ennis cleared every height at the first attempt, starting at 1.72m and finishing at 1.89m. She failed three times at 1.92m, but it was still a season's best. "I'm quite happy now," she said. "If I had had a bad jump here I would have been worried, but to jump 1.89m I feel a lot more comfortable. I know what I need to work on the high jump now."

Unlike her high jumping, Ennis's hurdling has been superb all season. But her race here was still a challenge because she was going up against the British record holder, Tiffany Porter, who came fourth at the World Championships in 2011. Before the race the two had a head-to-head record of two wins apiece, but Ennis now leads after winning in 12.92sec. Porter had been leading the race, but clipped the final hurdle.

"Running against Tiffany and beating her, it's all good for my confidence for the summer," Ennis said.

After the long jump here, Ennis plans to compete in one more competition before she heads off to the Olympic training camp. "There's nothing major for me to work on now, which is a great position to be in." The mounting expectation, she added, only told her that she was doing things right.

Porter is certain of her Olympic place, but she was furious with herself, perhaps even a little embarrassed at being beaten in a big race by a heptathlete.

But she was far from the only top athlete to struggle in the conditions, which were difficult all day. The world 400m hurdles champion, Dai Greene, came perilously close to making a mess of his own final, when he clipped a hurdle coming around the final bend.

Rhys Williams, two lanes outside Greene, also hit a hurdle and crashed to the track. It was a wacky race. Hanna- Barbera could have animated it.

Greene, a cool sort who knows how to keep his head, got his arms entangled with Nathan Woodward, who was flying along in the lane inside him. Woodward, who admitted that he should have had second place in the bag, lost his stride and clattered into the last hurdle.

Greene realised the danger he was in, and decided to slow down and add an extra stride to his pattern. The decision paid off. He went on to win, though his time of 49.47sec was a lot slower than he wanted.

"It wasn't there," Greene said. "I wanted to go faster, but I haven't done as many races as I would like to this season." Mainly though, he was just feeling relieved. "Everyone assumes you are going to make the team but all it takes is for one thing to go wrong and you could be out of the mix."

Woodward was overtaken by Greene's training partner, Jack Green, who took the second Olympic slot. Woodward will join the unhappy ranks of the athletes who are going to Helsinki for the European Championships next week. There they will have one more chance to try and get the 'A' qualifying standard and secure Olympic selection.

Christine Ohuruogu, on the other hand, insisted that she always knew she was going to make the Olympics. She duly won the 400m in 51.89sec, 0.02sec ahead of Shana Cox.

Chris Tomlinson will also be there. He finished third in the long jump, behind Greg Rutherford and JJ Jegede with his best jump being his last. It was 7.89m, 31cm shy of the 'A' standard. Rutherford won with 8.12m, but he has jumped 8.35m this season.

"I need to go back and think about what happened and move on," Tomlinson said. "I am definitely rusty around the take-off board, I just need to develop some confidence."

He wondered if it had been a error on his part not to compete earlier in the season. "Possibly it was a mistake," he admitted. "But I have got the Europeans this week so I will go out there and give it my all."